In this paper, a class of adaptive control systems is to be studied, in which the identification loop is closed over communication networks. The network-induced delays caused by the communication network are then inevitable and randomly time-varying in general. And these delays between controller and identifier can make a mess of the transmitted packet sequences which may deteriorate the control performance even destabilize the system. Obviously, the randomly time-varying delay is a key problem in networked adaptive control systems, and a strategy using the concept of fixed maximum delay is presented to avoid this problem. The adaptive system is proven to be convergent if such strategy is to be used. After that, with a view to further improve the performance, another modified strategy is proposed and the simulation results verify its validity and practicability.